UPS made a green effort recently by adopting 40 new hydraulic hybrid vehicles (HHVs) to its fleet in two U.S. cities.

The new HHVs, which are developed by Freightliner Custom Chassis Corporation (FCCC) and Parker Hannifin Corporation, will be deployed in Baltimore, Maryland and Atlanta, Georgia. Twenty vehicles will be sent to each city.

The HHVs have 35 percent greater fuel efficiency and 30 percent CO2 reduction compared to conventional diesel-powered vans. The HHVs run on a fuel-efficient diesel combustion engine and an advanced series hydraulic hybrid. The action of braking creates energy, and this energy is stored in the hydraulic high-pressure accumulator. There is an option to turn off the engine and use the energy stored in the accumulator, which can lead to 90 minutes less of engine run time on a trip.

"Our long-term goal is to minimize our dependence on foreign energy, and one way we will get there is through the deployment of a wide variety of technologies and designs in our fleet," said Mike Britt, UPS director of alternative fuel vehicle engineering. "As early adopters of this technology, we are very pleased with the significant fuel economy and emission reductions that come from the HHVs."

The deployment was partially funded by the U.S. Department of Energy's Clean Cities program. UPS employees in Baltimore will receive their HHVs immediately while those in Atlanta will get their vans sometime before the end of 2012.